Injector plunger seat sealing means



July 3, 1956 YERVANT H. KURKJIAN 2,752,920

INJECTION PLUNGER SEAT SEALING MEANS Filed Oct. 29, 1952 /MS ATTORNEY United States Patent() i INJECTOR PLUNGER SEAT SEALING MEANS Yervant H. Kurkjian, Clifton, N. J., assignor to Kurk Products Co., Clifton, N. J., a corporation of New Jersey Application October 29, 1952, Serial No. 317,549

3 Claims. (Cl. 12S- 261) This invention relates to a plunger type medicament injector for internal use, and has for one of its objects the production of an injector plunger seat sealing means to provide an air tight seal therefor.

A further object of this invention is the production of an injector plunger seat sealing means and a locking means to retain the plunger in an air tight sealed condition upon the seat which is engaged by the plunger head of an injector.

Other objects and advantages of the present invention will appear throughout the following specication and claims.

In the drawing:

Figure l is a side elevational View of an injector;

Figure 2 is a longitudinal sectional view thereof, certain parts being shown in elevation, the plunger being in a retracted sealed position upon its seat;

Figure 3 is a transverse sectional view taken on line 3 3 of Figure 2;

Figure 4 is a fragmentary longitudinal sectional View of a modified form of the invention;

Figure 5 is a fragmentary longitudinal sectional view of a further modified form of the invention;

Figure 6 is a fragmentary longitudinal sectional view of another modified form of injector.

By referring to the drawing in detail, it will be seen that 10 designates the injector casing which comprises a relatively large medicament containing chamber 11 at one end thereof and a shank portion 12, as shown in Figures l and 2. The chamber 11 is adapted to contain a measured quantity of medicament, such as medicament jelly 13. The outer end of the chamber 11 is open and may be closed by means of a conventional snap closure disc or cap 14 having an inturned annular flange 15 which is adapted to snapdit into the annular channel 16 formed in the outer face of the casing 10, as shown in Figure 2. The closure disc or cap 14 is formed of resilient plastic and provides an air tight closure at the outer end of the casing 10. This closure disc or cap14 retains the medicament in the chamber 11 and may be removed to permit the ejection of the medicament from the injector, when it is desired to do so.

A plunger seat 17 is formed at the inner end of the chamber 11, upon which is preferably mounted a resilient or semi-soft washer 18 of suitable material. The shank 12 is provided with a longitudinally extending bore 19 of smaller diameter than the chamber 11, thereby defining the seat 17, as shown in Figure 2. A plunger rod 20 extends longitudinally through the bore 19 and beyond the inner end of the shank 12. A plunger head 21 is carried by the plunger rod 20 and is adapted to abut the washer 18 when the plunger is retracted and is adapted to eject the medicament from the chamber 11 when the cap 2,752,920 Patented J uly 3, `1'956 ice,

14 is removed and the plunger is extended through the chamber 11. The plunger is of a diameter to freely move through the chamber 11, and to fit at against the washer 18 at the will of an operator.

The plunger rod 20 is provided with a knob 22 at its outer extremity beyond the shank 12 and is also provided with a threaded portion 23 intermediate the ends of the plunger rod 20, as shown in Figure 2. A knurled abutment element or nut 24 is carried by the plunger rod 20 and is adapted to be threaded upon the threaded portion 23 and to abut the end 25 of the shank 12 to draw the plunger head 21 to a tight sealing position upon the washer 18 which is carried by the seat 17. It should be understood that the plunger is drawn .inwardly of the casing 10 as the nut 24 is threaded thereon in the direction of the shank 12. This constitutes a pulling action to pull the plunger head 21 tightly against the washer 18 upon the seat 17 and thereby provides an air tight seal at the inner end of the chamber 11. The cap 14 provides an air tight seal at the outer end of the chamber 11. In this way the medicament`13 will be retained in its moistencd condition until theinjector is to be used. The casing 10 and plunger rod 20 constitute companion members for the purpose of locking the plunger head upon the seat by means of the abutment element or nut 24.

In Figure 4 there is shown a modified form of the invention wherein the plunger rod 26 carries a transverse wedge 27 for abutting engagement with the end of the casing shank 28 to draw the plunger head 29 to an air tight sealing position upon the gasket 30 which gasket is carried by the seat 31 in a manner similar to the form shown in Figure 2. The wedge 27 may be tied to the shank by means of a chain 27al to prevent the wedge from being lost.

In Figure 5 there is shown a further modified form of the invention wherein the plunger rod 32 carries a spring latch 33 having a rounded casing contacting end 34. The latch 33 may be depressed within the notch 35 of the plunger rod 32 tofacilitate the sliding of the plunger. The plunger may be retracted and locked by means of the end 34 engaging the end of the shank 3d to tightly seal the plunger head 37 upon the washer seat 38.

In Figure 6 there is shown another modified form of the invention wherein the casing 39 and seat 40 are formed of semi-hard plastic or other semi-hard material, and the plunger head 41 is formed of hard plastic or other hard material. This provides a semi-hard seat 42 against which the hard plunger head 41 is adapted to be drawn to con stitute an air tight seat therefor. The 'type of means shown in Figures 2, 4 and 5 may be used in this structure shown in Figure 6 to draw the head 41 upon the seat 40.

I claim:

1. An injector comprising a casing having a medicament containing chamber provided with an open outer end, said chamber having a seat at its inner end, a plunger head adapted to engage said seat and slidable in said chamber for ejecting medicament from said chamber through said open outer end, a plunger rod carrying said plunger head and slidably mounted in said casing and protruding beyond one end of said casing, said casing and said plunger rod constituting companion members, a threaded abutment element carried by one member, the other companion member being threaded to thereby co-operate with said threaded abutment element, said threaded abutment element abutting the other companion member and pulling said plunger rod and plunger head toward said seat and tightly sealing and locking said head in air tight locked engagement with said seat to seal the inner end of said chamber, and a removable closure carriedvby the outer end of said casing for sealing the open outer end of said chamber.

2. An injector as defined in claim 1, wherein said seat is formed of semi-soft material, and the plunger is formed of hard material.

3. An injector as defined in claim 1, wherein said seat is formed of semi-hard material, and the plunger is formed of hard material.

'UNITED STATES PATENTS Dodge Sept. 8, 1914 Morgan Feb. 7, 1928 Aas Aug. 7, 1928 Hagemeier Dec. 21, 1937 Oclassen et a1 Nov. 25, 

